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Atomic Insights into Aluminium‐Ion Insertion in Defective Anatase for Batteries
Author(s) -
Legein Christophe,
Morgan Benjamin J.,
Fayon Franck,
Koketsu Toshinari,
Ma Jiwei,
Body Monique,
SarouKanian Vincent,
Wei XianKui,
Heggen Marc,
Borkiewicz Olaf J.,
Strasser Peter,
Dambournet Damien
Publication year - 2020
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.202007983
Subject(s) - anatase , vacancy defect , intercalation (chemistry) , ion , titanium , materials science , aluminium , electrode , electrochemistry , interstitial defect , hydroxide , chemical physics , doping , inorganic chemistry , chemistry , crystallography , optoelectronics , metallurgy , photocatalysis , biochemistry , organic chemistry , catalysis
Aluminium batteries constitute a safe and sustainable high‐energy‐density electrochemical energy‐storage solution. Viable Al‐ion batteries require suitable electrode materials that can readily intercalate high‐charge Al 3+ ions. Here, we investigate the Al 3+ intercalation chemistry of anatase TiO 2 and how chemical modifications influence the accommodation of Al 3+ ions. We use fluoride‐ and hydroxide‐doping to generate high concentrations of titanium vacancies. The coexistence of these hetero‐anions and titanium vacancies leads to a complex insertion mechanism, attributed to three distinct types of host sites: native interstitial sites, single vacancy sites, and paired vacancy sites. We demonstrate that Al 3+ induces a strong local distortion within the modified TiO 2 structure, which affects the insertion properties of the neighbouring host sites. Overall, specific structural features induced by the intercalation of highly polarising Al 3+ ions should be considered when designing new electrode materials for polyvalent batteries.